I got a new sensor form an online aircon shop, weighed in at around £40 delivered. Job was easy. Had to remove undertray, and side protection cover and the sensor is really easy to get to. Not too tight either, just a nice bit of pressure on the spanner and it was loose.
Plugged in new one, crossed my fingers and started the car. Immediately hear the compressor clutch kick in and BAM, nice cold air.
I'm chuffed, mostly because its hit 24 degrees here...!!